TNNI1 / Troponin I, slow skeletal muscle · Western blot design guide

Design a Western Blot for TNNI1

Source-linked TNNI1 Western blot protocol options, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-TNNI1 WB antibodies. Everything you need to plan the experiment before you commit precious samples.

Evidence assembled September 2026 · For research use; verify linked source records and product datasheet before use

Western blot protocol sheet for TNNI1: expected band ~21.7 kDa, hero antibody M07080-1, catalog values and labelled standard workflow; separate PMC comparisons on the guide — Printable **TNNI1** Western blot protocol sheet — expected band ~21.7 kDa, antibody M07080-1, controls and PMC citations. Open the full TNNI1 WB guide →

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TNNI1 Western Blot Experimental Design Guide

Expected bands, source-linked protocol options, controls and antibodies — the at-a-glance facts below, then the full design guide.

Must know before running

	Expected band	~21.7 kDa
	Gel	12–15% (standard starting point)
	Positive control ⓘ	Skeletal muscle (IHC candidate; verify WB) +1 more
	Negative control ⓘ	Adipose tissue (IHC candidate; verify WB)

Important caveats

Reasons your observed band may differ from the expected size.

	PTM	Phosphorylated + Acetylated
	Caveat	Phosphorylation-state controls
	Gene-set association	MSigDB Hallmark membership
	Isoform	1 isoform(s)

Section 1

Source-Linked TNNI1 Western Blot Protocol Options

The M07080-1 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.

Recommended Western blot protocol parameters
Sample / lysate	Human fetal heart lysate (catalog M07080-1)
Gel %	12–15% (standard starting point)
Load	20–30 µg total protein per lane; optimize for abundance (standard starting point)
Transfer	Short semi-dry transfer; verify retention (standard starting point)
Membrane	0.45 µm PVDF (standard starting point)
Blocking	5% milk or 5% BSA in TBST (standard starting point)
Primary antibody	M07080-1; use the WB datasheet starting dilution (standard starting point)
Primary incubation	Overnight at 4 °C (standard starting point)
Secondary antibody	Species-matched HRP conjugate at validated dilution (standard starting point)
Secondary incubation	1 h at room temperature (standard starting point)
Wash	3 × 5 min in TBST (standard starting point)
Detection	ECL; bracket exposures to avoid saturation (standard starting point)

Section 2

What Is the Expected TNNI1 Western Blot Band Size?

TNNI1 is predicted at 21.7 kDa; acetylation and phosphorylation are listed, but their effects on band migration are not demonstrated.

What am I looking at on my blot?
Band near 21.7 kDa	Consistent with the predicted TNNI1 polypeptide.
Slightly offset band near 21.7 kDa	May reflect altered migration, but the effect of the listed modifications is unestablished.
Doublet near 21.7 kDa	Could represent differently modified TNNI1; distinct bands are not demonstrated.
Band in skeletal muscle lysate but absent from another sample	Consistent with differing abundance of this muscle protein; confirm band identity.

💡Expected TNNI1 appearanceUniProt predicts a 21.7 kDa TNNI1 band; no empirical band size is supplied, and any band should be checked with a suitable positive control and antibody specificity controls.

How each factor affects band size
UniProt predicted mass	Places the expected polypeptide band near 21.7 kDa.
187-residue polypeptide	Defines the chain underlying the predicted 21.7 kDa mass.
N-acetylproline at residue 2	Its effect on apparent migration is not established.
Phosphoserine at residue 58	Its effect on apparent migration is not established.

Why is my band missing or off?
Situation	Likely cause	Next action
No band in lysate	TNNI1 may be scarce in the sampled tissue.	Include a skeletal muscle positive control and check sample loading.
Band higher than expected	Band identity is uncertain; the listed modifications do not establish a measurable shift.	Compare with a positive control and verify antibody specificity.
Band lower than expected	Band identity or sample integrity is uncertain.	Check sample integrity and verify antibody specificity.
Multiple bands	Different modification states are possible but unresolved by the supplied evidence.	Compare bands with a positive control and verify antibody specificity.
Weak or no signal	Low TNNI1 abundance or insufficient detection sensitivity.	Check loading, antibody performance, and a skeletal muscle positive control.
Fragments below expected size	Sample degradation is possible; no TNNI1 cleavage product is specified.	Check sample handling and compare with a fresh positive control.

Source: UniProt P19237 Human Protein Atlas product datasheet (M07080-1)

Experiment evidence

Western blot images showing TNNI1 band

M07080-1 · TNNI1

A07080-1 · TNNI1

← swipe / scroll for more images →

Real WB data behind the band-size expectations in this section.

Sample controls for TNNI1 Western blot

🧪HPA-IHC candidate guidance (verify in WB): For positive controls for TNNI1 in Western blot, you can use skeletal muscle lysate, which shows high expression in HPA.

Positive control: Skeletal muscle (IHC candidate; verify WB)

Negative control: Adipose tissue (IHC candidate; verify WB)

Loading controls: Run GAPDH, β-actin, and a total-protein stain alongside the samples.

⚠️Feasibility: A tissue negative control is feasible because HPA reports TNNI1 as not detected in adipose tissue.

HPA tissue expression evidence for TNNI1

Comprehensive Human Protein Atlas IHC scoring per tissue. Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.

Higher expression tissues · candidate positive controls from IHC

Tissue	Cell type	Level	Evidence	Source
Skeletal muscle	myocytes	High	Protein (IHC)	HPA →
Testis	spermatogonia cells	Medium	Protein (IHC)	HPA →

Lower expression tissues · IHC evidence, not confirmed WB-negative controls

Tissue	Cell type	Level	Evidence	Source
Adipose tissue	adipocytes	Not detected	Protein (IHC)	HPA →
Adrenal gland	glandular cells	Not detected	Protein (IHC)	HPA →
Appendix	glandular cells	Not detected	Protein (IHC)	HPA →
Bone marrow	hematopoietic cells	Not detected	Protein (IHC)	HPA →
Breast	adipocytes	Not detected	Protein (IHC)	HPA →

Section 3

Advanced TNNI1 Western Blot Tips

Deeper troubleshooting and optimisation questions for TNNI1, answered from its protein features.

How should TNNI1 band migration be interpreted?

Band shift · Use the separately labelled calculated mass and catalog-observed evidence above. A sequence annotation does not establish an observed migration shift. Verify target identity with orthogonal controls.

Are multiple TNNI1 isoforms expected?

Isoforms · The supplied UniProt record lists one isoform and no alternative sequence. Multiple bands should not be assigned to TNNI1 isoforms based on this record alone.

Which phosphorylation site should a TNNI1 phospho-specific blot target?

PTM · UniProt lists phosphoserine at position 58. Check that the antibody recognizes this site, and verify its numbering convention: UniProt coordinates may differ from antibody or paper numbering.

UniProt lists N-acetylproline at position 2. Use UniProt sequence numbering when comparing this site with antibody or paper descriptions. This modification alone does not establish a resolvable band shift.

TNNI1 has a listed phosphoserine at UniProt position 58. A site-specific phospho signal reports recognition of that modified site; it should not be treated as a direct measure of total TNNI1. Verify the antibody's site and numbering convention before comparing signals.

Does this guide establish induction of TNNI1?

Induction · No general induction response is established by this guide. A pathway or gene-set association is not evidence of induction in a particular specimen. Verify the relevant treatment and control in a target-specific experiment.

How should transfer be checked for TNNI1?

Transfer · Standard workflow guidance: verify transfer efficiency for the intended target size before interpreting a weak signal. Use total-protein assessment and optimize transfer for the membrane, gel and apparatus; the labelled catalog values take precedence.

How should blocking be optimized?

Blocking · Standard workflow guidance: follow the M07080-1 datasheet where specified. Otherwise compare 5% milk or 5% BSA in TBST; for a phospho-specific assay start with BSA. Optimize background and specific signal with matched controls.

How should TNNI1 be quantified?

Quantitation · Standard workflow guidance: quantify only a validated target band within the linear exposure range. Use consistent sample preparation and loading, retain biological replicates, and avoid interpreting saturation or loading differences as regulation.

Should TNNI1 run at exactly 21.7 kDa?

Interpretation · 21.7 kDa is the predicted mass; no observed band position is supplied. UniProt lists acetylation and phosphorylation, but their presence alone does not establish a visible shift or explain a different apparent mass.

The supplied features do not identify an observed band position or establish the cause of extra bands. TNNI1 binds actin and tropomyosin, but that interaction alone does not identify an extra band. Check band identity before attributing it to the listed modifications or binding partners.

Boster reagents

TNNI1 Western Blot Antibodies

Catalog antibodies with Western blot application and product-specific WB images. Evaluate suitability with the reported sample, controls and experimental conditions.

Real WB data Western blot analysis of TNNI1 expression in Human fetal heart lysate.

Anti-TNNI1 Rabbit Monoclonal Antibody

Cat # M07080-1

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Real WB data

Western blot analysis of TNNI1 using anti-TNNI1 antibody (A07080-1). Electrophoresis was performed on a 5-20% SDS-PAGE gel at 70V (Stacking gel) / 90V (Resolving gel) for 2-3 hours. The sample well of each lane was loaded with 30 ug of sample under reducing conditions. Lane 1: human HepG2 whole cell lysates, Lane 2: human U-87MG whole cell lysates. After electrophoresis, proteins were transferred to a nitrocellulose membrane at 150 mA for 50-90 minutes. Blocked the membrane with 5% non-fat milk/TBS for 1.5 hour at RT. The membrane was incubated with rabbit anti-TNNI1 antigen affinity purified polyclonal antibody (Catalog # A07080-1) at 0.5 μg/mL overnight at 4°C, then washed with TBS-0.1%Tween 3 times with 5 minutes each and probed with a goat anti-rabbit IgG-HRP secondary antibody at a dilution of 1:5000 for 1.5 hour at RT. The signal is developed using an Enhanced Chemiluminescent detection (ECL) kit (Catalog # EK1002) with Tanon 5200 system. A specific band was detected for TNNI1 at approximately 22 kDa. The expected band size for TNNI1 is at 22 kDa.

Anti-TNNI1 Antibody Picoband®

Cat # A07080-1

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Both listed anti-TNNI1 antibodies report human reactivity and have WB images. M07080-1 is shown with human fetal heart lysate; A07080-1 is shown with human HepG2 and U-87MG lysates and a band near 22 kDa. Evidence is limited to the supplied product captions.

Which to pick: Choose M07080-1 for the documented fetal heart lysate context, or A07080-1 for the documented HepG2 or U-87MG lysate contexts. A07080-1 also provides detailed WB conditions, including a 0.5 μg/mL primary antibody concentration. Neither caption establishes performance in other samples.

Source: BosterBio TNNI1 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.

References

UniProt Consortium. UniProt entry P19237.
Human Protein Atlas. TNNI1 tissue expression.
PMC5554260 — target-verified WB comparison
PMC7034401 — target-verified WB comparison
PMC7274895 — target-verified WB comparison